Skip to Content

Hydrogen and Jack: error starting audio driver

2 replies [Last post]
Joined: 06/08/2011


I need some good advice to get Hydrogen working together with Jack. First I launch and start Jack (1.9.7) via QJackCtl. When Jack is running I launch Hydrogen (, set the AUDIO SYSTEM to "Jack" and click "OK". Now Hydrogen shows an error message ("error starting audio driver") and in QJackCtl's connections window Hydrogen only appears in MIDI tab, not in AUDIO tab. The same error occurs when I launch Hydrogen from commandline ("hydrogen -d jack").

  No demo song or click in Hydrogen can be played until setting the AUDIO SYSTEM in Hydrogen back to "ALSA".

I also tried to change the"<jack_port_name>" in hydrogen.conf from "alsa_pcm:" to "system:". But without success again.
Hydrogen and Jack both were included in Ubuntu-Studio 11.04.

Any ideas?

thijs's picture
Joined: 04/20/2010

can you post your jack config here ?



Joined: 06/08/2011

The jack config as shown in QJackCtl:

10:05:12.991 JACK startet...
10:05:12.993 /usr/bin/jackd -n(voreinst.) -v -dalsa -r44100 -p128 -n2 -m -Xraw -D -Chw:0,0 -Phw:0,0

When Jack is running, I launch Hydrogen from command line, either with "hydrogen -djack" or "hydrogen". Now several messages in different colors appear (in terminal):

no message buffer overruns`(voreinst.)'
server already active
Failed to start server(E) JackOutput
init Unknown status with JACK server.
Cannot connect to server socket err = Datei oder Verzeichnis nicht gefunden
Cannot connect to server socket
jack server is not running or cannot be started
(E) JackOutput init Unknown status with JACK server.
(E) H2Core::AudioOutput* H2Core::createDriver(const QString&) Error starting audio driver [audioDriver::init()]
(E) void H2Core::audioEngine_startAudioDrivers() Error starting audio driver
(E) void H2Core::audioEngine_startAudioDrivers() Using the NULL output audio driver
(E) void H2Core::audioEngine_startAudioDrivers() m_pMainBuffer_L == NULL
(E) void H2Core::audioEngine_startAudioDrivers() m_pMainBuffer_R == NULL
(E) void H2Core::audioEngine_setupLadspaFX(unsigned int) nBufferSize=0
(E) NullDriver setBpm not implemented yet
(E) LocalFileMng loadDrumkit Load Instrument: Data file /home/drummer/.hydrogen/data/temp/drumkit.xml not found.

Hydrogen comes up with the message "error starting audio driver". No sound, no transport in Hydrogen

Starting Hydrogen with "hydrogen -dalsa" while jack is not running, only few messages were shown in terminal:

(E) void* H2Core::alsaAudioDriver_processCaller(void*) XRUN

Sound is OK, but latency is to high (that's why I try to use Jack).